Figure 4.
Effect of iPSC-CENV on the proliferation of human dermal fibroblasts (HDFs). (A) After serum starvation, cells were treated with iPSC-CENVs for 48 h in serum-free condition. The population of active HDFs was determined by water-soluble tetrazolium salt-8 (WST-8) assay. The value of iPSC-CENV-untreated cells was regarded as 100%, and the populations of other treated groups were represented as relative values. (B) Serum-starved young (under passage number 5, P5) and senescent (over passage number 28, P28) HDFs were treated with particle number 2 × 109/mL of iPSC-CENVs for 48 h in serum-free condition, respectively, then the active cell populations were determined by WST-8 assay. Statistical significance (* p < 0.05, ** p < 0.01, and *** p < 0.005 compared to the iPSC-CENV-untreated group) was determined using Student’s t-test. Error bars indicate the standard deviation of triplicate experiments.